The present invention relates to a digital data recording system and, more particularly to a recording and reproducing system for recording digital data on recordable optical discs.
It has been known that there is a technique for management information to check whether or not data is recorded in physical blocks on recordable optical discs (refer to, for example, Japanese Patent Laid-open Nos. 2005-190539 and No. 2005-4912)
As an example of apparatus for recording digital data in a recording medium or reproducing digital data from a recording medium, there has been known a recording and reproducing apparatus for DVD-RAM as defined in “Standard ECMA-272: 120 mm DVD Rewritable Disc (DVD-RAM)” ECMA, 1999 (pages 43 to 55).
When an optical disc is loaded into the recording and reproducing apparatus, or the power for the apparatus is turned on, the apparatus first reads out disc management information data recorded in a disc management area DMA or the like that is stored in lead-in and lead-out areas so as to check whether the optical disc has been physically formatted. If the optical disc has not been physically formatted, the apparatus stands by until a physical format command is received from a higher-level device.
If the optical disc has been physically formatted, the recording and reproducing apparatus performs recording preparation processing, such as calibration or logical integrity verification, and then waits for a command from a higher-level device. Upon receiving any command from a higher-level device, the apparatus performs predetermined processing in response to the command. For instance, when receiving a record command, the recording and reproducing apparatus converts a format of the user data into a predetermined data format, and then records the data in a predetermined position on an optical disc. When receiving a reproduction command, the apparatus reconverts data recorded in a predetermined position on an optical disc into user data, and then reproduces the data for output to a higher-level device.
When receiving a command to unload an optical disc, the recording and reproducing apparatus stops rotation of a disc, and then perform discharge processing to discharge the disc from the apparatus.
Generally, in an optical disc recording and reproducing apparatus having a defect management function, user data recording processing includes integrity verification processing in which recorded data is reproduced to verify its validity. When it is determined as a result of the integrity verification processing that the validity of the recorded data is not sufficiently obtained, replacement processing is performed to dispose the user data in a spare area instead of a user area, thereby improving reliability of an optical disc.
According to the specification of ECMA-272, the correlation information of the user area and spare area addresses showing the result of the replacement processing is managed in the disk management area DMA as a defect list.
Next generation type optical discs, BD-R, which have been introduced in recent years and provides a large capacity with blue rays, have the same properties of recordable optical discs as DVD-R, and also provides a defect management system performing the random recording and replacement process in the same manner as DVD-RAM. Because of the configuration, management for checking whether any data is recorded in user areas on discs is performed by a space bit map (also referred to as space management information hereinafter).
Japanese Patent Laid-open Publication No. 2005-190539 describes a disc management information recording system for recordable optical discs, which is effective in recording and updating optical disc management information including space bit map on optical discs. The Publication, however, does not give any description on a restoration method for obtaining, from the past disc management information, disc management information that corresponds to a current optical disc, or secures integrity with a current optical disc. Such method is required in cases where it is impossible to properly read out desired disc management information, specifically the latest space bit map, from an optical disc upon loading an optical disc or setting up an optical disc recording and reproducing apparatus, or where disc management information has not been recorded on an optical disc since a high-level device fails to be properly terminated.
Japanese Patent Laid-open Publication No. 2005-4912 describes a disc management information recording system for recordable optical discs that is also effective in recording and updating optical disc management information including space bit map on optical discs and recovers disc management information when its integrity can not be obtained in a setting while recording and updating the management information. Such system, however, have the problem that it takes a long time to update optical disc management information.